Glance out of any window in Great Britain and you are likely to spot a bird. Birds live in every habitat, from mountain top to city street. The UK's Breeding Bird Survey has noted 209 different species. Set up a bird table and you will attract a variety of common birds to identify by their size, behaviour, call or distinctive markings. Look out for birds such as the house sparrow, once very common, which has seen a 62 per cent decline in its population since the 1970s, according to the Royal Society for the Protection of Birds (RSPB).
The wood pigeon, common as muck
This plump bird, around 41cm long, has a blue-grey back and wings, a pinkish tinge to its breast and distinctive splashes of white at the back of its neck and along its wing edges. In 2005, BBC news described the wood pigeon as the "most common" bird in the UK.
The male chaffinch has pink underparts, a bold red face and a greyish cap. The female is a more muted brown. Both male and female are around 14cm long and have two bars of white on each wing, divided by a black stripe. The chaffinch has a varied, trilling, musical call.
You will typically spot a blackbird foraging on the ground for insects, worms and fallen berries. Around 24cm long, adult males are glossy black, with yellow beaks and rings around their eyes. Females are brown and lack the yellow features. Young birds are brown too, but with speckled underparts. Blackbirds have a mellow, musical song.
Only 10cm long, the tiny wren has a chestnut brown back, wings marked with dark bars, pale underparts and a distinctive white line above its eye. Its round body and needle-like beak are set off by a tail it often holds upright. Wrens feed close to the ground, on insects and spiders.
Male and female robins look alike. They are around 14cm long, with brown backs and wings, bright red breasts and short, pointed beaks. Immature robins have chests mottled in shades of brown. Robins sing their high-pitched, fluting songs throughout the year.
Carrion crows are around 46cm long, with dusty, black feathers and large, jabbing beaks. The RSPB describes carrion crows as: "One of the cleverest and most adaptable of our birds." You will usually see carrion crows singly or in pairs, unlike the similar-looking rook, which typically belongs to a flock.
The blue tit is a quick-moving, lively bird, around 12cm long. It is boldly marked, with a blue back and a yellow breast. Its white face is framed by a black border, with a black bar across the eye. Its head is capped by another patch of blue. Blue tits sing readily, with a high-pitched, piping call.
Larger than a blue tit, the great tit's body is around 14cm long. It has a green back and black head with distinctive white cheek patches. You can find great tits singing their two-note songs in most parts of the UK, though not in the Northern and Western Isles of Scotland.
You will often spot starlings gathered in large, noisy flocks. From a distance, a starling looks a little like a small blackbird, but at closer quarters, its dark plumage shines with oily greens and purples. Its whole body, particularly its underside, is mottled and speckled with white.
Once very common, the house sparrow is becoming a rarer sight (see Reference 2). About 14cm in length, it has a brown back barred with black lines, a grey breast and bold patches of white on its cheeks. The adult male's head is capped with grey and it has a black or grey bib beneath its beak (see notes to editor).